Controller for electric motors.



Nu. 66l,.972. Patented Nov. 20, I900. F. W. GARRETT.

CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Junu 5, 1900.)

(No Model.) 3 Sheets-Sheet l.

WITNESSES: 3 MENTOR \M ATTORNEY.

we NORRIS PETERS cu. PNOYO-LIYNQ. WASHKNGTQN. n. c.

No. 66l,972. Patented Nov. 20, I900. F. W. GARRETT.

CONTROLLER FOR ELECTRIC MOTORS.

(Application filed Jun 5. 1900.)- (No Model.) 3 SheetsSheet 2.

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No. 66l,972. Patented Nov. 20, I900.

F. W. GARRETT.

CONTROLLER FOR ELECTRIC MOTORS. (Application filed June 5, 1900.)

3 Sheets-Sheet 3.

an ATTORNEY.

m: News PETERS cu, PHOYO-LITNO. \VASHNGTON. o c.

UNITED STATES PATENT Center FRANK XV. GARRETT, OF JOHNSTOVVN,PENNSYLVANIA, ASSIGNCR TO THE LORAIN STEEL COMPANY, OF PENNSYLVANIA.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 661,972, dated November20, 1900.

Original application filed March 26, 1900, Serial No. 10,151. Dividedand this application filed June 5, 1900. $erial No. 19,144. LNo model.)

To all whom it may concern.-

Be it known that I, FRANK W. GARRETT, of Johnstown, in the county ofCambria and State of Pennsylvania, have invented a new and usefulImprovement in Controllers for Electric Motors, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, which form a part of this specification.

ro Myinvention has relation to certain newand useful improvements incontrollers for electric motors, and is more particularly designed toprovide means for carrying into effect the method of control describedand claimed in my pending application, Serial No. 10,151,

filed March 26, 1900, of which the present application is a division.Generally considered,

7 that method consists in arranging the motors in two or more parallelgroups, starting them from a position of rest with the motors of eachgroup connected in series, and then by intermediate circuit changesconnecting the motors of each group in parallel, certain of suchintermediate changes being effected in one group in advance of similarchanges in the other group or groups and while the latter are activelyconnected in circuit. The intermediate circuit changes above referred toare preferably of such character as not to require the use of externalresistance in connection therewith.

Broadly considered, my invention consists in a controller arranged toconnect the motors in multiple groups and having series parallelingcontacts for each group arranged in such a manner as to effect certaincircuit changes in one group in passing from series to parallel inadvance of similar changes in the other group or groups.

It also consists in a controller having contacts arranged to eifeet thepeculiar circuit conditions, which are preferably employed in theintermediate steps in passing from series to parallel, and also in thenovel construction, arrangement, and combination of parts, all ashereinafter described, and pointed out in the appended claims, referencebeing had to the accompanying drawings, forming a part of thisspecification.

Figure 1 is a diagram showing a controller development and circuitarrangement suitable for the practice of my invention. Fig. 2

is a graphic representation of the motor-circuits in the severalpositions of the controllerdrums; and Figs. 3, i, and 5 are plan ularsections of the controller-dru m, showingthe relative positions of theircontacts at certain positions of the drums.

In the figures, M, M M and M indicate four electric motors, whosearmatures are designated, respectively, as A, A A and A and theirfield-coils F, F F and F. T indicates the connection to the trolley orsupply side of the circuit. G, whenever seen, indicates a groundconnection. CS designates the canopy-switches; F13, a fuse-box; LA, alightning-arrester, and CC a choke-coil. These parts are of any usualcharacter and form no part of my invention.

C C represent in development the two controller-drums.

BOC is the blow-out coil therefor, and RS the reversing-switch.

R R designate artificial resistance-boxes for connection in circuit withthe motors in starting from or approaching a position of rest.

The drums C C in so far as their mechanical arrangement is concerned areof a wellknown type,beingintergeared with each other So in anywell-known or usual manner to move in unison by the operation of asingle lover or handle. Each drum C C carries six gron ps of contacts,the individual contacts of each group being electrically connected witheach other, while the several groups are electrically disconnected. Thecontacts of the first group on each drum are marked a to c", inclusive;those of the second group 0 to c", inclusive; those of the third group 0to c, inclusive; those of the fourth group o to 0 inclusive; those ofthe fifth group 0 to 0 inclusive, and those of the sixth group to 0'inclusive.

While the number of contacts is the same 5 on both drums, as is alsotheir general arrangement or grouping, it will be noted that thecontacts o c, 0 a, 0 0 and 0 on the drum C are longer than thecorresponding contacts on the drum C in that on the drum G thesecontacts terminate on or slightly beyond the indicated position 5,whereas on the drum 0' they extend to a point slightly beyond the dottedline indicating the position It will also be noticed that the contacts 0a 0 0 c, c 0 e (1 and c on the drum C are longer than the correspondingcontacts on the drum 0, being extended farther to the left, so thatwhile on the drum 0 these contacts are first engaged when the drum isturned to the position 6 on the drum C they are first engaged at theposition 52. The contact-fingers which cooperate with the contacts ofthe drum 0 are designated by the numbers 10 to 22, inclusive, while thefingers which cooperate with the contacts of the drum 0 are designatedby the reference characters 10 to 22", inclusive. The reversing-switchBS is of well-known type and need not be described, being shown only forthe purpose of com pleting the electrical connections. In tracing thecircuits hereinafter it will be assumed that its series ofcontact-fingers are engaging the contacts on the dotted line markedahead and designated by 2 z 2 the, to Contact-fingers 10, 11, and 12 areelectricallyconnected to the resistance-box R to connect in circuit,respectively, a decreasing amount of the resistance therein, and fingers1O, 11, and 12 are similarly connected to the resistance-box R. Finger12 is also connected to one terminal of the field-coil F and finger 12is similarly connected to one terminal of the field-coil F Finger iselectrically connected to finger l4, and the latter is connected to oneterminal of the field-coil F. Finger 13 is connected to finger let andthe latter to one terminal of the field-coil F Finger 15 is connected toone side of the field-coil F and linger 15 to the corresponding side offield-coil F. Fingers 16 and 16 are respectively connected to armaturesA" and A through the reversing-switch, and the return connections fromsaid armatures through said switch are made, respectively, with thefingers 1E) and 1t). Fingers l7 and 17 are respectively connected tofield-coils F and F Fingers 1S and 1S are respectively connected toarmatu res A and A the return con nections also through said switchbeing to the fingers 21 and 21, respectively. Finger 21 is connected tofinger 20 and linger 21 to finger 20. Fingers 22 and 22 are connected inmultiple with the blow-out coil BOO, which is connected with the trolleyor supply side of the main circuit. L is a lead, grounded as indicated,and to which resistance-boxes R; and R are connected. The first group ofcontacts of each drum (1 C is grounded on the shaft thereof.

From the above description of the connections it will be seen that thedrum C controls motors M and It, while the drum C controls the motors Mand M, and that the two drums areelectrically connected in multiple.

The operation is as follows: Starting from a position of rest with thecontroller-druins in their first positions, the currentfrom the trolleypasses through the blow-out coil and to the fingers 22 22 of the drumsin multiple. Inasmuch as the circuit through the contacts of one drum issubstantially the same as the circuit through the other drum and its twomotors in all except a few positions, it will be sufficient, exceptas tothose positions, to trace one circuit. From the linger the circuit isthrough contacts 0 and c finger 21 to finger 23 of the reversing-switch,contacts :2: m finger 25, to and through armature A, linger 24 to linger26, to linger 18, contacts c finger lfl, finger 31., contacts .2 linger33, to and through armature A to linger 1:32, confacts 2" z, linger 3st,finger 10, contacts c 0 finger 1'7, field F, linger 14:, contacts c tr,finger 15, field F and through resistance-box R to ground. In thisposition thereli'ore the current passes through each pair of motors andthe resistance-box therefor in series. in position 2 the circuit is thesame, except that finger 10 engages contact c, and thereby shortcircuitsa portion of the resistance, and in position 3 the engagement of finger11 with corn tact c short-circuits a further section of the resistance.In position 1tho engagement of the finger 12 with the contact ashort-tdrcnits the entire resistance. In position 1-1 the only changewhich is effected is that the finger l5 bridges the contacts c and 0 andthereby short-circuits the field F, similar shortcircuit of field Ftaking place by the bridging of the finger l5 and its correspondingcontacts. In position 12 the fingers l4: and 15 lose their engagementwith contacts 0' and c", thereby cutting out the field F. Positions 1-1and 42 are not notch or running positions, but occur momentarily inpassing from notch position s to notch position 5. In position 5 finger13 engages the contact c and the circnit is through the two fields inmultiple, tho armature connections and circuits remaining as before. Asimilar multiple connection of the fields F F is of course effected. Inposition 51 the connections controlled by the drum 0 remain the same asin position 5; but

owing to the fact that the contacts 0, c, 0 0 and c of the drum C areshorter than the corresponding contacts of the drutn C, as abovedescribed, the circuit is entirely opened through the motors fill. M(See position 51 of Fig. 2, also Fig. 3.) At position 52 the connectionscontrolled. by drum (3 still remain the same as in position 5; but onthe drum 0 the fingers 11-, 15*, 16, 17, 18, 1f), 20, 21, and 22 engage,respectively, the contacts 0 0 c 0", 0, e 6 c and 0 thereby restoringthe series con noction of the fields F F and connecting the armatures AA in multiple. The circuit through the motors M M" is therefore asfollows: to linger 22", to contacts 0 0 and finger 21.. Here the currentdivides, one part passing from linger 21 to finger 27 of thereversing-switch, contacts .2 a, finger 29, armature A linger 28,

contacts a 2 finger 30, finger 18, contacts c, finger 17, field F fingerl t, confacts 0 0 finger field F, finger 12, and contact 0 to ground.The other part of the current passes from finger 21 to finger contacts 00 finger 1f), finger of the reversing-switch, contactsz z, finger 37,arm ature A", finger 36, contacts .2 .2 finger 38 to finger 16, andcontact 0 to contact 0 where its path unites with that of the firstbranch described. At position 53 the connections controlled by drum Cremain as in position 52; but the fingers of the drum C entirely loseengagement with the contacts of the drum O,and thereby open the circuitthrough the motors M and M (See position 53, Fig. 2, also Fig. 5.) Thenposition 6 is reached, the connections controlled bydrum O remain thesame as in position 52; but the fingers 12 and 14 to 22, inclusive, ofthe drum 0 are engaged, respectively, with the contacts 0 c 0 0 c, 0 0 0C and 0 This restores the series connection of the fields F F andconnects the armatures A A in multiple, the circuitbeing similar to thattraced in position 52that is to say, the current divides between fingers21 and 20, one part passing by way of finger 21 and the reversing switchto and through armature A, thence back through said switch tothe finger18 and contacts 0 0 while the other part passes by way of finger 20,contacts 0 0 finger 19, and the reversing-switch through armature A,thence back through said switch to finger 16, to contacts c 0 where thetwo paths unite and the current passes in series through fields F F byway of finger c field F, finger 14, contacts 0 0 finger 15, field Ffinger 12, and contact 0 to ground. Positions 51, 52, and 53 are notnotch positions; but position 6 is a notch posit-ion. In position 61 thefingers 16, 20, and 21 and 16, 20, and 21 have lost engagement with therespective contacts c 0 and 0 which breaks the circuits to armatures Aand A the other connections remaining as in position 6. At position 62fingers 13 and 13 engage their respective contacts c, and therebyshort-circuit the fields A and A. At position 63 the fingers 14: and 15and 1 1 and 15 leave the contacts c C and thereby cut out the fields AA". Positions 61, 62, and 63 are not notch positions. The elements ofthe motors are now in condition for connection in full multiple, andthis is effected at position 7 by the engagement of the contacts 0', 0 00 and 0 by the corresponding fin gers of each drum. Vithouttracing outthe circuits in full at this time it will be readily seen that thecurrent at each drum will divide between the fingers 19 and 21 or 19 and21, one part going through the reversingswitch by a path similar to thatbefore traced,

through armature A or A thence back to finger ,18 or 18, contacts 0 0finger 17 or 17, field F or F and contact 0 to ground, and the otherpart through the reversing-switch,

armature A 01 A, back to finger 16 or 16, to contacts c 0 finger 15 or15, to field F or F to finger 13 or 13, to contact a, to ground.

It will be obvious that my invention is not limited to the detailedarrangement of contacts and circuit connections which have been shownand described herein for the purpose of presenting a completeoperativodevice, but that other specific arrangements maybe readilydevised which will be equally within the spirit and scope of myinvention as pointed out in the appended claims.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. he combination with a plurality of electric motors, of a controllerarranged to connect said motors in parallel groups, and having contactsand connections for changing the motors of each group from series toparallel relation, said contacts being differently arranged forthe-different groups, whereby certain circuit changes are effectedsucce. sively in the different groups.

2. "he combination with a plurality of electric motors, of a controllerarranged to connect said motors in parallel groups, and having contactsand connections for changing the motors of each group from series toparallel relation, certain contacts in one group being of differentlength from the corresponding contacts of the other group or groups.

3. The combination with a plurality of electric motors, of a controllerarranged to connect the same in parallel groups, said controller havinga moving member for each of said groups, adapted to change theindividual motors thereof from series to parallel relation, and meanswhereby certain steps in such change are successively effected in thedifferent groups and without opening the circuit of more than one groupat a time.

a. The combination with a plurality of electric motors designed to beoperated in groups, of a controller therefor having a movable member foreach group of motors, each of said members having contacts forconnecting the motors of its group both in series and in parallel, andalso for connecting either the fields or armatures of said motors inparallel, with the other elements in series, the said contacts beingdifferently arranged on the different members to effect certain of saidcircuit conditions in one group in advance of a like effect in the othergroup or groups.

5. The combination with a plurality of electric motors, arranged to beoperated in groups, of a controller therefor, having a movable memberfor each group of motors, and connecting the several groups in parallel,each of said members having one position in which the motors of itsgroup are connected in series, a second position in which they areconnected in parallel, and intermediate positions which respectivelyconnect the fields in parallel and the armat-ures in series, and thenthe armatures in parallel and the fields in series, and

&

means whereby the said movable members effect the last-named circuitcondition successively in the different groups.

(5. The combination with a plurality of electric motors, arranged to beoperated in parallelgroups or pairs, of a controller having a drum foreach group or pair of motors, each of said drums having contacts andconnections for connecting its motors both in series, both in parallel,and also either the fields or armatu res only in parallel and in serieswith the remaining elements, and means for operating said drums

